Printer variable form length controller

ABSTRACT

An apparatus for and a method of electrically controlling the movement of the paper web in a printer is disclosed. Prior to initiating the form setting operation of the variable form length controller of the present invention, a first row of perforations on the paper web is manually aligned to the O line count position of the first form that is to be printed. Next, the operator initiates the form setting operation by setting the paper or form length in which the paper web is prepared, i.e., the total number of printable lines between successive rows of perforations, into a thumbwheel switch assembly. Circuitry is next enabled for selectively moving the paper web in preparation for the first line to be printed on line 1 or 4. Successive line feed signals from the printer controller are counted, compared to the form length set into the thumbwheel switch assembly and when the line count equals the form length an end-of-form signal is generated for selectively moving the paper web in preparation for the first line to be printed on line 1 or 4 of the next form to be printed. Provision is made for a single form feed signal from the printer controller to move the paper web in preparation for the first line to be printed on line 1 or 4 of the next form to be printed.

45] Dec. 24, 1974 PRINTER VARIABLE FORM LENGTH CONTROLLER [75] Inventor: James A. Taggart, Salt Lake, Utah [73] Assignee: Sperry Rand Corporation, New York, NY. 7

[22] Filed: Sept. 20, 1973 [21] Appl. No.2 399,230

[52] US. Cl. 197/133 R,lOl/93 C, 226/32,

235/92 PE [51] Int. Cl B41j 15/04 [58] Field of Search 197/127, 128, 130, 133;

101/93 C; 226/29, 32; 235/92 CA, 92 CT, 92 9 MP, 92 PE, 151.22

Primary ExaminerRobert E. Bagwill Assistant ExaminerPaul T. Sewell Attorney, Agent, or Firm Kenneth T. Grace; Thomas J. Nikolai; John P. Dority [5 7 ABSTRACT An apparatus for and a method of electrically controlling the movement of the paper web in a printer is disclosed. Prior to initiating the form setting operation of the variable form length controller of the present invention, a first row of perforations on the paper web is manually aligned to the 0 line count position of the first form that is to be printed. Next, the operator initiates the form setting operation by setting the paper or form length in which the paper web is prepared, i.e., the total number of printable lines between successive rows of perforations, into a thumbwheel switch assembly. Circuitry is next enabled for selectively moving the paper web in preparation for-the first line to be printed on line 1 or 4. Successive line feed signals from the printer controller are counted, compared to the form length set into the thumbwheel switch assembly and when the line count equals the form length an end-of-form signal is generated for selectively moving the paper web in preparation for the first line to be printed on line 1 or 4 of the next form to be printed.

'Provision is made for a single form feed signal from 6 Claims, 6 Drawing Figures Pmfimennim Y 3.856.128

PRlNTER MECHANISM INTERFACE SIGNALS Fig. 3

E E j 82 E g NOR Q: l- B B O m l m Z w 8O 98 g 6 Q 6 0 2 E F. E F. m g RESET SET RESET SET 0 fir '2 m NAND NAND 3 O: CLOSED=SKIP"OFF" 74 96 v OPEN= SKIP "0N" +5v 72 94 SET CONDITION NOR NOR WHEN CLOSED [6O [7O [76 [78 A! 5 AH g A2| P A2 3 M2 B1 A22 5 8 A3 A|3 A23 0 A4 AI4 A24 El Bll B2! J B2 Bl2 B22 5 B3 BIB 5 B23 ,2 g 5 B4 Bl4 5 B24 m 5 CI 1: cu t Cal 8 t3 c2 8 012 2 e22 m E52 03 3 013 8 023 E c4 cm 024 PRINTER VARIABLE FORM LENGTH CONTROLLER BACKGROUND OF THE INVENTION In the prior art it is known that printers are often required to print upon paper webs of varying sizes or form lengths. Accordingly, many arrangements have been devised to permit the adjustment of form length to accommodate form length variation. In a typical arrangement, such as in the C. Barbagallo, et al., US. Pat. No. 3,174,610, acommon drive shaft may drive both the paper web and an endless paper tape the latter containing punched holes indicative of' the lines at which the movement of the paper web is to be arrested for printing. Such arrangement utilizes cumbersome mechanical form control be replaced by an electrical form control.

SUMMARY OF THE INVENTION In the present invention the paper web is driven by a well-known arrangement of a continuously operating electrical motor, belt drive coupled through a mechanical clutch. The clutch is released, i.e., isengaged, to permit the belt drive to move the paper web in one line increments by an escapement mechanism controlled by a solenoid that is, in turn, driven by the novel variable form length controller of the present invention. Prior to operation of the printer, the paper web is manually aligned along a first row of perforations that define the Ohm count position of the first form or page, i.e., de-

fined as that portion of the paper web between successive rows of perforations. Then the total number of printable'lines of the form, i.e., the form length FL, is loaded into a three wheel thumbwheel switch assembly.

A momentarily closed set switch loads the form length that was set into the thumbwheel switch assembly into a latch circuit or holding register while a line counter is cleared to 0: a comparator compares the contents of the line counter and the latch circuit generating an end-of-form or match signal when the contents of the line counter and the latch circuit are equal. Each successive line feed signal from the printer controller moves the paper web one line and increments the line count LC held in the line counter by 1. When the line count equals the form length, LC =F L, the comparator and the end-of-form signal clears the line counter to 0. Provisions are made for permitting the end-of-form signal to cause the paper web drive to selectively skip three lines whereby the first line tobe printed would be the fourth line below the row of perforations instead of the normal first line below the row of perforations.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a well-known paper advance mechanism incorporated in a printer utilizing the present invention.

FIG. 2 is an end vie-w of the escapement mechanism, line feed clutch assembly incorporated in FIG. I.

FIG. 4 is a front view of the variable form length control panel of the present invention.

FIG. 5 is an illustration of a typical timing diagram of the variable form length controller of the present in-' vention illustrating the operating relationship of the respectively associated circuitry of FIG. 3 duringa form setting operation.

FIG. 6 is an illustration of a typical timing diagram of the variable form length controller of the present invention illustrating the operating relationship of the re- .spectively associated circuitry of FIG. 3 during printer operation by the printer controller.

DESCRIPTION OF THE PREFERRED EMBODIMENTS With particular reference to FIG. 1 there is presented a perspective view of a well-known paper advance mechanism incorporated in a printer utilizing the present invention. Paper web 10 is divided into successive forms of pages 10a, 10b by transverse rows of perfora tions 14, 14a which permit paper web 10 to be folded in a zig-zag fashion prior to and subsequent to the print- -ing of characters thereon. In addition, paper web 10 controller of the present invention.

has lines of perforations 12 along the edges thereof which perforations 12 are spaced apart and adapted to be engaged by the sprockets of a pair of sprocket belts 16, only one of which is visible in the drawing, supported by corresponding pairs of sprocket wheels 18, 20. Sprocket wheels 18 are driving pulleys fixed to driving shaft 22. Line feed clutch assembly 24 includes the mechanism whereby driving shaft 22 and sprocket wheels 18 are driven by a continuously operating electrical motor, belt'drive coupling through a mechanical clutch. Sprocket wheels 20 are idling or driven pulleys V rotatably mounted on drive shaft 26, being driven by the sprocket belts 16.

Prior to operation of the printer, and, correspondingly, the variable form length controller of thepresent invention, the paper web 10 is manually aligned along a first row of perforations 14 that define the 0 line count position of the first row of page 10a; a form or page being defined as that portion of the paper web 10 between successive rows of perforations 14, 14a. The manual alignment of paper web 10 at the 0 line count position is accomplished by using the paper position adjustment knob 28. Knob 28 is rotated until the row of perforations 14 is aligned with the alignment mark 11 in nonmovable alignment bracket 13. located near the surface of paper web 10 on the lefthand side of the form 10a in a clearly visible location and as near as possible to the surface of paper web 10 to minimize parallax. After the alignment of paper web 10 to the 0 line count position of the first form 10a along row of perforations 14, knob 28 is'manually released and is not used thereafter to advance paper web 10. All further paper web 10 advancement is then under control of the variable form length controller of the present invention.

Advancement of paper web 10 is accomplished via the output signal from line feed amplifier 30 (see FIG. 3) at solenoid 32. To better understand the following discussion of the line'feed clutch assembly 24 of FIG. 1 reference should be had to FIG. 2 in which there is presented an end view of the escapement mechanism of the line feed clutch assembly 24. Input shaft 34 of clutch assembly 24 has rotational torque applied thereto by means of the input pulley 36, belt 38 and the printer motor (not illustrated). The rotation of the driving or output shaft 22 is controlled by separating the input shaft 34 and the output shaft 22 by the use of a clutch collar 42. When solenoid 32 is activated, pawl 44 is retracted from stop collar 46 allowing stop collar 46 to rotate and coupling between input shaft 34 and output shaft 22 is accomplished. When solenoid 32 is de-energized, pawl 44 is forced against stop collar 46 by return spring 48. When a stop collar tooth 47 is forced against the shoulder of pawl 44 by the rotation of stopcollar 46, stop collar 46 is restrained from further rotation. The output shaft 22 is rotated an amount of thumbwheel switch assembly 60 settings for various form lengths assuming (vertical) line spacing to be 1/6 inch.

TABLE A FORM, LENGTH (VERTICAL INCHES) TOTAL LINES SKIP SWITCH PER FORM PosmoN CORRESPONDING THUMBWHEEL SWITCH ASSEMBLY SETTING IN PRINTABLE LINES l/6 (MIN) 4 5 166% (MAX) OFF .001 ON 018 OFF 030 ON 027 OFF 033 ON 036 OFF 054 ON 060 OFF 078 ON 084 OFF 108 ON 126 OFF 300 ON 594 OF 750 OFF 999 equal tothe angle between adjacent teeth 47 on stop collar 46. When this angle of rotation is applied to sprocket wheel 18, the paper web will be advanced an amount determined by the diameter .of sprocket wheel 18. In this particular case, the paper web advancement is 1/6 inch. When solenoid 32 is energized, it is done so for only sufficient time to allow clutch collar 42 to rotate so that the tooth 47 on stop collar 46 clears the tip of pawl 44 and then solenoid 32 is deenergized allowing pawl 44 to fall against stop collar 46 so that its rotation is restricted to the spacing between adjacent teeth 47.'This results in a vertical advancement of paper web '10 one line of, e.g., l/6 inch.

With particular referenceto. FIG. 3 there is presented a block diagram of the variable form length controller of the present invention. As stated above, prior to operation of the printer under control of printer controller 58, and/or the variable form length controller of the present invention, paper web 10 is manually aligned along the first row of perforations 14 that define the 0 line count position of the first form 10a. Next, the form setting operation is initiated by setting the total number of printable lines of the form, i.e., the fo'rmlength FL,

. into a three-wheel thumbwheel switch assembly 60, the individual thumbwheel switches being adjusted such that they represent the number of printable lines per form. Printable lines are defined as those lines on a form upon which the printer is allowed to print. The total number of lines per form and the printable lines per form are not necessarily the same unless skip switch 64 is in the closed position. Skip switch 64, when in the open position, provides for a 3 line margin on each side of a row of perforations 14, 14a. Thus, when skip Switch 64 is in the open position the number of printable lines per form 10a, 10b is 6 less than the number of lines per form 10a, 10b. Table A illustrates examples two-position ON-OFF skip switch 64 the function of such switches to be discussed hereinbelow.

The individual thumbwheel switches of thumbwheel. switch assembly 60 produce an electrical output in a binary coded decimal (BCD), each individual thumbwheel switch having one input terminal and four output terminals. The input terminal is utilized to supply the voltage for sensing and the output terminals contain the electrical signals in a binary code that represents the unique code corresponding to that thumbwheel switch position. There are 10 positions on each thumbwheel switch and each position is numbered consecutively starting with -0 and ending with 9. Thus, there are a total of 12 output signals (A1, A2, A3, A4, B1, B2, B3, B4, C1, C2, .C3, C4) from the thumbwheel switch assembly 60 thatelectrically represent the settings of the three individual thumbwheel switches.

With particular reference to FIG. 5 there is presented an illustration of a typical timing diagram of the variable form length controller of the present invention il' lustrating the operating relationship of the respectively associated circuitry of FIG. 4 during a form setting operation. After the thumbwheel switch assembly 60 is set to represent the desired form length of forms 10a, 10b, the operator depresses set switch 62. Set switch 62 generates a pulse that is coupled to latch 70, NOR gate 72 and-NAND gate 74. The pulse from set switch 62 gates the signals A1 C4 from thumbwheel switch assembly 60 into latch 70. The signals in latch are subsequently compared by comparator 76 to the corresponding binary coded decimal signals in line counter 78. An equality comparison of the signals in latch 70 .and line counter 78, LC FL, causes comparator 76 to couple a match or end-of-form (EOF) signal to NOR gate 72 which, inter alia, clears line counter 78 to a count of 0 in preparation for the line count sequence. With-skip switch 64 in its open condition, the set switch 62 pulse enables NAND gate 74 which, in turn, toggles Flip-Flop (FF) 80 to its set condition-FF 80 is only used during the form setting operation when skip switch 64 is set in the open position for causing a three line advance of paper web so that the first characters printed on form 100 will appear four lines below the row of perforations 14 rather than the normal one line below the row of perforations 14. The mechanical timing signal MT from printer controller 58 and the set output from FF 80 through NOR gate 82 enable NAND gate 84 causing line feed amplifier 30 to pulse solenoid 32 advancing paper web 10 one line. The output from NAND gate 84 also increments line counter 78 and skip counter 88 one line cou'nt. Each time the mechanical timing signal MT enables NAND gate 84, line feed amplifier 30 pulses solenoid 32 advancing paper web 10 one line and increments line counter 78 and skip counter 88 one line count. When skip counter 88 reaches a skip linecount of 3, NAND gate 90, along with the output from FF .80, is enabled causing NOR gate 94 to clear skip counter 88 to a count of 0, clears FF 80 and through NOR gate 72 clears line counter 78 I to a count of 0.

94 clears skip counter 88 to a line count of 0 terminating the output of NAND gate 92 whileNOR gate 72 clears line counter 78 to a count of 0 in preparation for the start of printing on the new form 10b. At this time paper web 10 is positioned such that the first line of characters to be printed upon form 10b will be printed upon the fourth line below row of perforations 14a.

If in the above described operation skip switch 64 had been in its'closed position rather than its open position, NAND gate 96 would'not have been enabled by its end-of-form signal EOF from comparator 76 such that FF 98 would not have been set and, accordingly,

In contrast to the above described form setting operation,'-if skip switch 64 had been in the closed condition when set switch 62 was depressed, NAND ga'te74 would not have'been enabled, and, accordingly, the

.three line advance caused by the-setting of FF 80 would be positioned whereby the first line below the row of' perforations 14. This above described operation illustrated by the timing diagram of FIG. 5 completes the form setting operation whereby the variable form line controller is ready for printer operation under control of printer controller 58.

With particular reference to FIG. 6 there ispresented an illustration of a typical timing diagram of the variable form length controller of the present invention illustrating the operating relationship of the respectively associated circuitry of FIG. 4 during'aprinter operation under control of printer controller 58. Each time printer controller 58 concurrently couples a mechanical timing signal MT to NAND gate 84 and a line feed signal LP to NOR gate 82,'NAND gate 84 is enabled causing line feed amplifier to pulsesolenoid 32 causing paper web 10 to advance one line. The enabling of NANDgate 84 also increments line counter 78 one line count. When the contents of latch 70 and line counter 78 are equal, LC LF, comparator 76 couples an end-of-form signal EOF to NOR gate 72 and NAND gate 96. NOR gate 72 clears line counter 78 to a count of 0 while NAND gate 96, with skip switch 64 in its open position, is enabled toggling FF 98-to its set condition. The set output of FF 98 through NOR gate 82-enables, at NAND gate 84, each mechanical timing signal MT to pulse line feed amplifier 30 causing solenoid 32 to advance paper web 10 one line count. Concurrently, the enabling of NAND gate 84 at each mechanical timing signal MT increments line counter 78 and skip counter 88 one line count. Skip counter 88 is enabled via OR gate 86 while OR gate 86 is enabled when either FF 80 or FF 98 is in the set condition. With FF 80 in the cleared condition and FF 98 in the set condition, successive mechanical timing signals MT increment skip counter 88 to a line count of 6, which, along with the output from FF 98, enables NAND gate 92 coupling its output to NOR gates 94 and 72. NOR gate skip counter 88 would not have caused paper web 10 to skip the three printable lines at the end of form 10a and the first three printable lines at the beginning of form 10b, above and below, respectively, row of perforations l4a. Further, if instead of coupling the line feed signal LP to NOR gate 82 printer controller 58 had coupled a form feed signal to NOR gate 82, the form feed signal, which is a continuous enabling signal, and each mechanical timing signal MT would have enabled NAND gate 84 to'pulse line feed amplifier 30 causing solenoid 32 to advancepaper web 10 one line count until comparator 76would have generated its end-ofform signal EOF such that printer operation would be similar to that as described above.

Thus, the variable form length controller of the present invention permits the rapid adjustmentof printer operation to any form length through a thumbwheel switch assembly and control of the first row of characters to be printed on the first or fourth line of the form. Accordingly, it is apparent that applicant has provided herein anovel means of electrically varying the operation of a printer to correspond to the particular form length of the paper web utilized.

What is claimed is:

I. A printer variable form length controller providing line advance signals for advancing a paper web upon which characters-are to be printed, comprising:

line advance gating means for providing a line advance signal output when enabled;

meansfor coupling timing signals as the first input to said line advance gating means;

a skip counter;

means for coupling the line advance signal output from said line advance gating means to said skip counter for counting said line advance signals;

a skip flip-flop; V

means for coupling the output of said skip counter as means for coupling a first output of said skip flip-flop as the second input to said line advance gating means; i

set switch means coupled to the second input of said skip flip-flop for enabling said line advance gating means to couple said line advance signals to said skip counter to toggle said skip counter to a predetermined skip count and then to toggle said skip flip-flop and to disable said line advance gating means.

2. A printer variable form length controller providing line advance signals for advancing a paper web upon which characters are to be printed, comprising:

line advance gating means for providing a line advance signal output when enabled;

means for coupling timing signals as the first input to said line advance gating means;

a skip counter;

means for coupling the line advance signal output from said line advance gating means to said skip counter for counting said line advance signals;

means for coupling the output of said skip counter as a first input to said skip flip-flop;

means for coupling a first output of said skip flip-flop .as the second input to said line advance gating means; a

set switch means;

skip switch means;

form setting gating means;

means for coupling said set switch means as a first input to said form setting gating means;

means for coupling the output of said form setting gating means as a second input to said skip flipp;

means coupling said skip switch means as an enabling second input to said form setting gating means for enabling said set switch means to toggle said skip flip-flop whereby said skip flip-flop enables said line advance gating means to couple said line advance signals to said skip counter to toggle said skip counter to a predetermined skip count and then to toggle said skip flip-flop and to disable said line advance gating means.

3. A printer variable form length controller providing line advance signals for advancing a paper web upon which characters are to be printed, comprising:

line advance gating means for providing a line'advance signal output when enabled;

means for coupling timing signals as the first input to said line advance gating means;

a skip'counter; t

means for coupling theline advance signal output from said line advance gating means to said skip counter for counting said line advance signals;

means for'coupling the output of said skip counter as a first input to said skip flip-flop;

means for coupling a first output of said skip flip-flop as the second input to said line advance gating means; a

a thumbwheel switch assembly capable of assuming positions indicative of the form length of the forms into which said paper web is prepared for generating corresponding form length signals;

' a latch circuit for accepting and storing said form length signals;

a line counter for counting said line advance signals;

means for coupling said-form length signals from said thumbwheel switch assembly to said latch circuit;

line counter and generating an end-of-form signal when said comparison is equal;

an end-of-form gating means;

means for coupling said end-of-form signal as a first input to said-end-of-form gating means;

means for coupling said end-of-form signal to said line counter for resetting said line count to zero;

means for coupling the output of said end-of-form 10 vance gating means to couple said line advance signals to said skip counter to toggle said skip counter I to a predetermined skip count and then to toggle said skip flip-flop-and to disable said line advance gating means.

4. In a printer having a printer controller providing timing signals, avariable form length controller, comprising: V

advancing means for advancing apaper web, upon which characters are to be printed, one line upon receipt of a line advance signal;

a line advance gating means for providing a line advance signal output when enabled;

means for coupling said timing signal as the first input to said line advance gating means;

means for coupling the line advance signal output from said line advance gating means to said advancing means; means for coupling the first output of said skip flipflop as the enabling second input to said line advance gating means; a skip counter; v i means'for coupling the line advance signal output from said line advance gating means to said skip counter for incrementing said skip counter one line skip count; a skip gating means; means for coupling the output of said skip counter as the first input to said skip gating means;

means'for coupling the second output of said skip flip-flop as the second input to said skip gating means; means for coupling the output of said skip gating means to the first input of said skip flip-flop;

set switch means coupled to the second input of said skip flip-flop and through said line advance gating means enabling said timing signal to couple said line advance'signal to said advancing means and said skip' counter for incrementing said skip counter and enabling said skip gating means to toggle said skip flip-flop and to disable said line advance gating means.

timing signals, a variable form length controller, comprising: I

advancing means for advancing a paper web, upon which characters are to be printed, one line upon receipt of a line advance signal;

line advance gating means for providing a line advance signal output when enabled;

means for coupling said timing signal as the first input to said line advance gating means;

means for coupling the line advance signal output from said line advance gating means to said advancing means;

5. In a printer having aprinter controller providing means for coupling the first output of said skip flipflop as the enabling second input to said line advance gating means; a a skip counter;

' means for coupling the line advance signal output from said line advance gating means to said skip counter for incrementing said skip counter one line skip count;

a skip gating means;

means for coupling the output of said skip counter as an input to said skip gating means;

means for coupling the second output of said skip flip-flop as an input to said skip gating means;

means for coupling the'output of said skip gating means to the first input of said skip flip-flop;

a thumbwheel switch assembly capable of assuming positions indicative of the form length of the forms into which'said paper web is prepared for generating corresponding form length signals;

a latch circuit for accepting and storing said form length signals;

a line counter for counting said line advance signals;

means for coupling said form length from said thumbwheel switch assembly to said latch circuit;

means for coupling the line advance signal output from said line advance gating means to said line counter for incrementing said line counter one line count;

a comparator coupled to said latch circuit and to said line counter for comparing the form length stored in, said latch circuit to the line count stored in said line counter and generating an end-of-form signal when said comparison is equal;

an end-of-form gating means;

means for coupling said end-of-form signal as an input to said end-of-form gating means;

means for coupling said end-of-form signal to said line counter for resetting said line count to zero;

means for coupling the output of said end-of-form gating'means to the second input of said skip flipfloP; v

skip switch means for enabling said end-of-form sig nal at said end-of-form gating means totoggle said skip flip-flop and through said line advance gating means to enable said timing signal to couple said line advance signal 7 to said advancing means whereby said skip counter is incremented to enable said skip gating means to toggle said skip flip-flop and to disable said line advance gating means.

6. in a printer having a printer controller providing timing signals, line feed signals and form feed signals, a variable form length controller, comprising:

electromechanical means for advancing a paper web, upon which characters are to be printed, one line upon receipt of a line advance signal; 7 a line advance NOR gate;

' I .a line advance NAND gate for providing a line admeans for coupling the line advance signal output from said line advance NAND gate to said electromechanical means; Y

means for coupling said line feed signal as a first input to said line advance NORgate;

means for coupling said form feed signal as the second input to said line advance NOR gate;

means for coupling the first output of said three line skip flip-flop as a third input to said line advance NOR gate;

means for coupling-the first output of said six line skip flip-flop as a fourth input to said line advance NOR gate;

a skip counter;

means for coupling the line advance signal output from said line advance NAND gate to said skip counter for counting said line advance signals;

a skip counter enable OR gate;

a three line skip NAND gate;

a six line skip NAND gate;

means for coupling the output of said skip counter as e an input to said three line skip NAND gate and said six line skip NAND gate;

means for coupling the output of said skip counter enable OR gate as an enabling input to said skip counter;

means for coupling the second output of said three line skip flip-flop and said six line skip flip-flop as first and second inputs to said skip counter enable OR gate;

' means for coupling the second output of said three line skip flip-flop as an input to said three line skip NAND gate;

means for coupling the second output of said six line skip flip-flop as an input to said six line skip NAND gate;

means for coupling the output of said three line skip NAND gate tothe first input of said three line skip pp; 3

means for coupling the output of said six line skip NAND gate to the first input of said six line skip pp;

a skip counter reset NOR gate;

means for coupling the outputs of said three line skip NAND gate and said six line skip NAND gate as first and second-inputs to said skip counter reset NOR gate;

means for coupling the output of said skip counterreset NOR gate asa resetting input to said skip counter;

a thumbwheel switch assembly capable of assuming positions indicative of the form length of the forms into which said paper web is prepared for generating corresponding form length signals;

a latch circuit for accepting and storing said form length signals;

a line counter for counting said line advance signals;

means for coupling said form length signals from said thumbwheel switch assembly to said latch circuit;

means for coupling the line advance signal output from said line advance NAND gate to said line counter for counting said line advance signals;

a comparator coupled to said latch circuit and said line counter for comparing the form length stored in said latch circuit to the line count stored in said line counter and generating an end-of-form signal when said comparison is equal; an end-of-form NAND gate; an end-of-form NOR gate;

means for coupling said end-of-form signal as inputs means for coupling the output of said six line skip NAND gate as an input to said end-of-form NOR gate;

a form setting NAND gate;

skip switch means;

set switch means;

means for coupling said set switch as an enabling input to said form setting NAND gate and to said end-of-form NOR gate;

means for coupling said skip switch as an enabling input to said form setting NAND gate and to said end-of-forrn NAND gate; means for coupling said set switch to said latch circuit for enabling said latch circuit to accept and store said form length signals; said set switch means setting said three line skip flipflop and through said line-advance NOR gate and said line advance NAND gate enabling said timing signal to couple said line advance signals to said electromechanical means and to said skip counter for'incrementing said skip counter three line skip counts to enable said three line skip NAND gate to toggle said three line skip flip-flop and to disable said line advance NAND gate; said skip switch means enabling said end-of-form signal at said end-o f-form NAND gate to toggle said six line skip flip-flop and through said line advance NOR gate and said line advance NAND gate enabling said timing signal to couple said line advance signals to said electromechanical means and to said skip counter for incrementing said skip counter six line skip counts to enable said six line skip NAND gate to togglesaid six line skip flip-flop and to disable said line advance NAND gate.

UNE'REE) S'IATES PATENT ()FFiCE 'CERTEFEC,A'TE OF CORREQ'HGN Paten: No. 3,856, 128 Dated December 24, 1974 Invcntor(3) James A. Tagg art It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

IN THE PRINTED PATENT:

4 Column 9, Line 23, after "length" insert signal Column 11, Lines 14 and 15, delete in their entirety.

Signed and sealed this 4th day bf March 1975.

(SEAL) Attest s C. MARSHALL DANN RUTH C. MASON Coxmnissibner of Patents Arresting Officer and Trademarks 

1. A printer vaRiable form length controller providing line advance signals for advancing a paper web upon which characters are to be printed, comprising: line advance gating means for providing a line advance signal output when enabled; means for coupling timing signals as the first input to said line advance gating means; a skip counter; means for coupling the line advance signal output from said line advance gating means to said skip counter for counting said line advance signals; a skip flip-flop; means for coupling the output of said skip counter as a first input to said skip flip-flop; means for coupling a first output of said skip flip-flop as the second input to said line advance gating means; set switch means coupled to the second input of said skip flipflop for enabling said line advance gating means to couple said line advance signals to said skip counter to toggle said skip counter to a predetermined skip count and then to toggle said skip flip-flop and to disable said line advance gating means.
 2. A printer variable form length controller providing line advance signals for advancing a paper web upon which characters are to be printed, comprising: line advance gating means for providing a line advance signal output when enabled; means for coupling timing signals as the first input to said line advance gating means; a skip counter; means for coupling the line advance signal output from said line advance gating means to said skip counter for counting said line advance signals; a skip flip-flop means for coupling the output of said skip counter as a first input to said skip flip-flop; means for coupling a first output of said skip flip-flop as the second input to said line advance gating means; set switch means; skip switch means; form setting gating means; means for coupling said set switch means as a first input to said form setting gating means; means for coupling the output of said form setting gating means as a second input to said skip flip-flop; means coupling said skip switch means as an enabling second input to said form setting gating means for enabling said set switch means to toggle said skip flip-flop whereby said skip flip-flop enables said line advance gating means to couple said line advance signals to said skip counter to toggle said skip counter to a predetermined skip count and then to toggle said skip flip-flop and to disable said line advance gating means.
 3. A printer variable form length controller providing line advance signals for advancing a paper web upon which characters are to be printed, comprising: line advance gating means for providing a line advance signal output when enabled; means for coupling timing signals as the first input to said line advance gating means; a skip counter; means for coupling the line advance signal output from said line advance gating means to said skip counter for counting said line advance signals; a skip flip-flop; means for coupling the output of said skip counter as a first input to said skip flip-flop; means for coupling a first output of said skip flip-flop as the second input to said line advance gating means; a thumbwheel switch assembly capable of assuming positions indicative of the form length of the forms into which said paper web is prepared for generating corresponding form length signals; a latch circuit for accepting and storing said form length signals; a line counter for counting said line advance signals; means for coupling said form length signals from said thumbwheel switch assembly to said latch circuit; means for coupling the line advance signal output from said line advance gating means to said line counter for counting said line advance signal; a comparator coupled to said latch circuit and said line counter for comparing the form length stored in said latch circuit to the line count stored in said line counter and generating an end-of-form signal when said comparison is equal; an end-of-form gating means; means for coupling said end-of-form signal as a first input to said end-of-form gating means; means for coupling said end-of-form signal to said line counter for resetting said line count to zero; means for coupling the output of said end-of-form gating means to the second input of said skip flip-flop; skip switch means coupled to the second input of said end-of-form gating means enabling said end-of-form signal at said end-of-form gating means to toggle said skip flip-flop for enabling said line advance gating means to couple said line advance signals to said skip counter to toggle said skip counter to a predetermined skip count and then to toggle said skip flip-flop and to disable said line advance gating means.
 4. In a printer having a printer controller providing timing signals, a variable form length controller, comprising: advancing means for advancing a paper web, upon which characters are to be printed, one line upon receipt of a line advance signal; a line advance gating means for providing a line advance signal output when enabled; a skip flip-flop; means for coupling said timing signal as the first input to said line advance gating means; means for coupling the line advance signal output from said line advance gating means to said advancing means; means for coupling the first output of said skip flip-flop as the enabling second input to said line advance gating means; a skip counter; means for coupling the line advance signal output from said line advance gating means to said skip counter for incrementing said skip counter one line skip count; a skip gating means; means for coupling the output of said skip counter as the first input to said skip gating means; means for coupling the second output of said skip flip-flop as the second input to said skip gating means; means for coupling the output of said skip gating means to the first input of said skip flip-flop; set switch means coupled to the second input of said skip flip-flop and through said line advance gating means enabling said timing signal to couple said line advance signal to said advancing means and said skip counter for incrementing said skip counter and enabling said skip gating means to toggle said skip flip-flop and to disable said line advance gating means.
 5. In a printer having a printer controller providing timing signals, a variable form length controller, comprising: advancing means for advancing a paper web, upon which characters are to be printed, one line upon receipt of a line advance signal; line advance gating means for providing a line advance signal output when enabled; a skip flip-flop; means for coupling said timing signal as the first input to said line advance gating means; means for coupling the line advance signal output from said line advance gating means to said advancing means; means for coupling the first output of said skip flip-flop as the enabling second input to said line advance gating means; a skip counter; means for coupling the line advance signal output from said line advance gating means to said skip counter for incrementing said skip counter one line skip count; a skip gating means; means for coupling the output of said skip counter as an input to said skip gating means; means for coupling the second output of said skip flip-flop as an input to said skip gating means; means for coupling the output of said skip gating means to the first input of said skip flip-flop; a thumbwheel switch assembly capable of assuming positions indicative of the form length of the forms into which said paper web is prepared for generating corresponding form length signals; a latch circuit for accepting and storing said form length signals; a line counter for counting said line advance signals; means for coupling said form length from said tHumbwheel switch assembly to said latch circuit; means for coupling the line advance signal output from said line advance gating means to said line counter for incrementing said line counter one line count; a comparator coupled to said latch circuit and to said line counter for comparing the form length stored in said latch circuit to the line count stored in said line counter and generating an end-of-form signal when said comparison is equal; an end-of-form gating means; means for coupling said end-of-form signal as an input to said end-of-form gating means; means for coupling said end-of-form signal to said line counter for resetting said line count to zero; means for coupling the output of said end-of-form gating means to the second input of said skip flip-flop; skip switch means for enabling said end-of-form signal at said end-of-form gating means to toggle said skip flip-flop and through said line advance gating means to enable said timing signal to couple said line advance signal to said advancing means whereby said skip counter is incremented to enable said skip gating means to toggle said skip flip-flop and to disable said line advance gating means.
 6. In a printer having a printer controller providing timing signals, line feed signals and form feed signals, a variable form length controller, comprising: electromechanical means for advancing a paper web, upon which characters are to be printed, one line upon receipt of a line advance signal; a line advance NOR gate; a line advance NAND gate for providing a line advance signal output when enabled; a three line skip flip-flop; a six line skip flip-flop; means for coupling said timing signal as a first input to said line advance NAND gate; means for coupling the output of said line advance NOR gate as the second input to said line advance NAND gate; means for coupling the line advance signal output from said line advance NAND gate to said electromechanical means; means for coupling said line feed signal as a first input to said line advance NOR gate; means for coupling said form feed signal as the second input to said line advance NOR gate; means for coupling the first output of said three line skip flip-flop as a third input to said line advance NOR gate; means for coupling the first output of said six line skip flip-flop as a fourth input to said line advance NOR gate; a skip counter; means for coupling the line advance signal output from said line advance NAND gate to said skip counter for counting said line advance signals; a skip counter enable OR gate; a three line skip NAND gate; a six line skip NAND gate; means for coupling the output of said skip counter as an input to said three line skip NAND gate and said six line skip NAND gate; means for coupling the output of said skip counter enable OR gate as an enabling input to said skip counter; means for coupling the second output of said three line skip flip-flop and said six line skip flip-flop as first and second inputs to said skip counter enable OR gate; means for coupling the second output of said three line skip flip-flop as an input to said three line skip NAND gate; means for coupling the second output of said six line skip flip-flop as an input to said six line skip NAND gate; means for coupling the output of said three line skip NAND gate to the first input of said three line skip flip-flop; means for coupling the output of said six line skip NAND gate to the first input of said six line skip flip-flop; a skip counter reset NOR gate; means for coupling the outputs of said three line skip NAND gate and said six line skip NAND gate as first and second inputs to said skip counter reset NOR gate; means for coupling the output of said skip counter reset NOR gate as a resetting input to said skip counter; a thumbwheel switch assembly capablE of assuming positions indicative of the form length of the forms into which said paper web is prepared for generating corresponding form length signals; a latch circuit for accepting and storing said form length signals; a line counter for counting said line advance signals; means for coupling said form length signals from said thumbwheel switch assembly to said latch circuit; means for coupling the line advance signal output from said line advance NAND gate to said line counter for counting said line advance signals; a comparator coupled to said latch circuit and said line counter for comparing the form length stored in said latch circuit to the line count stored in said line counter and generating an end-of-form signal when said comparison is equal; an end-of-form NAND gate; an end-of-form NOR gate; means for coupling said end-of-form signal as inputs to said end-of-form NAND gate and said end-of-form NOR gate; means for coupling the output of said end-of-form NOR gate to said line counter for resetting said line count to zero; means for coupling the output of said end-of-form NAND gate to the second input of said six line skip flip-flop; means for coupling the output of said six line skip flip-flop; means for coupling the output of said three line skip NAND gate as an input to said end-of-form NOR gate; means for coupling the output of said six line skip NAND gate as an input to said end-of-form NOR gate; a form setting NAND gate; skip switch means; set switch means; means for coupling said set switch as an enabling input to said form setting NAND gate and to said end-of-form NOR gate; means for coupling said skip switch as an enabling input to said form setting NAND gate and to said end-of-form NAND gate; means for coupling said set switch to said latch circuit for enabling said latch circuit to accept and store said form length signals; said set switch means setting said three line skip flip-flop and through said line advance NOR gate and said line advance NAND gate enabling said timing signal to couple said line advance signals to said electromechanical means and to said skip counter for incrementing said skip counter three line skip counts to enable said three line skip NAND gate to toggle said three line skip flip-flop and to disable said line advance NAND gate; said skip switch means enabling said end-of-form signal at said end-of-form NAND gate to toggle said six line skip flip-flop and through said line advance NOR gate and said line advance NAND gate enabling said timing signal to couple said line advance signals to said electromechanical means and to said skip counter for incrementing said skip counter six line skip counts to enable said six line skip NAND gate to toggle said six line skip flip-flop and to disable said line advance NAND gate. 